NEW YORK -- Political gridlock is starting to whittle away at investor confidence.

Nearly three-quarters -- 72% -- of investors say the government shutdown, now in its eighth day, has begun to "diminish their confidence in the economy's recovery," according to a poll conducted by TD Ameritrade Holding Corporation.

Uncertainty, of course, is starting to take its toll on investors as the government budget impasse has dragged on and fears of a U.S. default have risen as the Oct. 17 deadline to raise the debt ceiling nears. Stocks are down again Tuesday and on track for their 11th decline in the past 14 sessions.

Other findings of the investor survey, which was conducted after Day Three of the shutdown last Thursday.

• 41% said they "haven't made changes to their investments," but may pull back if the budget standoff continues.

• 37% say the shutdown and debt ceiling issue "will pass quickly" so they have not yet taken any action.

• 12% say they are "taking advantage of buying opportunities" as a result of the downturn.

• 10% say they have "moved some money to cash."

"Some investors likely aren't adding positions or taking on new risk yet until there is a clear picture as to how the shutdown and debt-ceiling deadline will settle," says JJ Kinahan, chief strategist at TD Ameritrade."